Apparatus for cleaning and conditioning gravel



June 29, 1937. J. A. WEBB 2,085,283

APPARATUS FOR CLEANING AND CONDITIONING GRAVEL Filed Dec. 22, 1931 5 Sheets-Sheet 1 June 29, 1937. WEBB 2,085,283

APPARATUS FOR CLEANING AND CONDITIONING GRAVEL Filed Dec. 22, 1931 5 Sheets-Sheet 2 June 29, 1937. A. BB 2,085,283

APPARATUS FOR CLEANING AND CONDITIONING GRAVEL Filed Dec. 22, 1931 5 Sheets-Sheet 3 J. A. WEBB June 29, 1937.

APPARATUS FOR CLEANING AND CONDITIONING GRAVEL 5 Sheets-Sheet 4 Filed Dec. 22, 19

June 29, 1937. J. A. WEBB 2,085,283

APPARATUS FOR CLEANING AND CONDITIONING GRAVEL Filed Dec. 22, 19.31 5 $l leetssheet 5 nnnnnnnnnnnnnnnnn Patented June 29, 1937 UNITED STATES ATENT OFFI'E APPARATUS FOR CLEANING AND CONDI- TIONING GRAVEL 1 Claim.

vThisinvention relates to apparatus for cleaning and conditioning gravel, and the like.

An object of the. invention is to provide apparatus of the character specified whereby gravel and similar aggregate may be cleansed and conditioned and rendered marketable.

Another object is to provide apparatus of this characterwhereby gravel, as it comes from the bed, or pit, may be cleansed of clay, sand and loother foreign matter and screened so as to separate the finer aggregate from the coarser.

Another object is to provide apparatus of the character described whereby the aggregate, as screened, may be separated and the fine and 1:5 coarse aggregate delivered separately from the apparatus.

Another object is to provide, in an apparatus of the character described a novel type of traveling conveyor-screen for conveying and screening, the aggregate and novel means for regulating the tension of said screen, and the invention also comprehends means for agitating the aggregate as it moves along to facilitate the cleansing and screening thereof.

With the above and other objects in View, this invention has particular relation to certain novel features of construction, operation and arrangement of parts an example of which is given in this specification and illustrated in the accom- 30. panying drawings, wherein:-

Figure 1 shows a side elevation of the apparatus, shown partly in section.

Figures 2 and 3 show side views of types of screen supporting drums employed.

Figure 4 shows a plan view of the apparatus.

Figure 5 shows a cross sectional View taken on the line 5-5 of Figure 4.

Figure 6 shows a side view of a modified arrangement of the apparatus shown partly in sec- Figure '7 shows a plan view thereof.

Figure 8 shows a plan view of a modified form of screen.

Figure, 9 shows a fragmentary, diagrammati- 45. cal, end view, showing screen tensioning means employed.

. Figure 10 shows an enlarged, fragmentary end view thereof.

Figure 11 shows an enlarged, fragmentary,

50 sectional view of the screen.

Figure 1 2 shows an enlarged cross sectional view of another form of tensioning. means employed, and

Figure 13 shows a sectional view thereof, taken 5;); on the, line I.3l3 of Figure 12.

spective drums 2, 3 are the rotatable outer and 1 0;

inner idler rollers 5, 5 and 6, 6 respectively, alternate cables 4 pass over said rollers 5, 6, respectively, as shown in Figure 1, and pass them around the corresponding rotatable drumsl, 8

and also around the corresponding sheaves, 9, 15

of the tensioning devices I8, ll, hereinafter more fully described. The idler rollers are grooved to hold the cables in proper alignment and are provided so as to space the cables apart to provide room for said tensioning devices. The cables 4 20 form not only a conveyor to convey the gravel, or other aggregate, delivered thereto, from the chute l2, but also form a screen to screen the aggregate. This screen together with the side members I, form a chute along which the gravel may pass, as more clearly illustrated in Figures 2 and 3. The drums 2, 3 may have smooth, concaved surfaces, as shown in Figure 2, in which case the cables 4 will lie closely together, or they may have convex surfaces and spaced, annular,

"0 grooves 3 for the cables 4 to hold the cables spaced apart as shown in Figure 3. The cables used will be, preferably, of the twisted wire type, as shown in Figures 11 and 13 and cables of this form will have the external, spiralled, grooves as 0,

I 4 between the wires so that in case the cables are arranged close together, as shown in Figure 2, the water, sand, dirt, and the like may pass through the grooves 14 of the screen. The spacing of the cables, as shown in Figure 3, will per- 40 mit the finer gravel also to pass through the screen.

The shaft l5 of the drum 3 is extended and has a band wheel I6 fixed thereon. There is a motor l I whose shaft has a pulley I8 fixed thereon and a belt l9 operates over the pulleys l6, l8 and transmits rotation from the latter to the former whereby the screen cables are moved. The screen formed by the upper horizontal runs of the cables moves the gravel along from the delivery chute l2, at one end, to the receiving hopper 2!] at the other end. This hopper has a grate-like bottom 2| and over this bottom there is a. transverse nozzle pipe 22 having downwardly directed nozzle openings through which a washing fluid may be delivered onto the gravel in the hopper 28. This fluid and the detritus wash from the gravel will enter, the channel 23 underneath and will be conveyed by said channel into the tubular conveyor 24 at the forward end of the frame. There are suitable agitator rollers 4' underneath, and in contact with, the horizontal runs of the cables, which are polygonal in form and which are rotated by the frictional contact of the cables therewith, and which vibrate the screen as they rotate to shake the detritus, and the like, from the gravel and these agitator rollers may be grooved to receive the cables 4.

Behind these rollers are the forwardly declining guard boards 25 which shield said agitator rollers and prevent the aggregate from adhering to the rollers, or from collecting between the rollers 24, and the cables 4.

The sides I have the inwardly declining shields 25, or the forwardly inclining shields 2'! which throw the aggregate on the screen inwardly and prevent it from congesting between the sides I and the screen cables.

The water and detritus falling through the screen will fall into the collecting hopper 2'! and be discharged out through the side delivery chute 28.

On the shaft |5 are the pulleys 29 and 38 over which operate the belts 3| and 32 the former of which operates over and drives the pulley 33 fixed on the shaft 34 and the latter of which operates over and drives the pulley 35 which is fixed on the shaft 36. On the shaft 36 there is a. cylindrical brush 37 arranged in front of the hopper 28 and composed of stiff bristles, preferably of steel wires.

Underneath the brush 3! there is a platform 38 which declines forwardly and whose ends are adjustable up and down by means of the adjusting screws 39. Hinged to the respective ends of the platform 38 are the platform sections 48, 4| the free margin of the former of which lies on the grate 2| and the free margin of the latter of which may be adjusted up or down by means of the adjusting rod 42. The aggregate collecting in the hopper 28 will pass therefrom over said platform and this platform, and its end sections 48, 4| may be adjusted so as to control the accumulation of the aggregate in said hopper 28. The aggregate passing over said platform will be delivered thereby into the declining, hopper-like chute 43 and will be thereby delivered into the conveyor 24. This conveyor has an axial shaft 44, rotatably mounted therein having a spiralled brush 45 thereon and the inner end of said brush has a pinion 46 fixed thereon in mesh with and driven by a similar beveled pinion 41 fixed on the inner end of the shaft 34. The outer, or forward, end of the conveyor 24 has a side, discharge opening 48 leading from which there is a declining grate 49 arranged to deliver the aggregate,

discharged through said opening, onto the traveling conveyor, whereby the aggregate is delivered from the apparatus.

The gravel or sand to be screened and cleansed will pass from the delivery chute l2 onto the screen and will be conveyed thereby toward the hopper 28. The agitator rollers 4 will be rotated by the frictional contact of the cables 4 therewith and on account of their polygonal shape these rollers 4 will vibrate said cables and cause the finer particles to pass through the screen. The rollers 4 may be grooved, if desired, to maintain the cables properly spaced. If the cables are small and arranged closely adjacent the screen may be used to screen very fine sand from coarser sand or gravel, or the cables may be so spaced as to screen fine gravel from coarser gravel. As the aggregate passes over the grate 2| it may be flushed with water from the nozzle 22 and the clay, and detritus, adhering thereto washed therefrom, the water and detritus passing on down through the chute 23 and out through the conveyor 24. If desired the platform 38 may be adjusted down to the level of the grate 2| so that the gravel will pass freely from the hopper 20 onto the platform 38 and the delivery of said gravel along and from said platform may be controlled by a suitable adjustment of the forward end section 4| or the platform 38 may be elevated above the level of the grate 2| with the free edge of the section 48 resting on said grate and this will cause the gravel, or other aggregate to accumulate in the bottom of the hopper 2| for a more thorough Washing and said accumulated aggregate will be gradually crowded up over said section 40 onto said platform 38. Over the platform 88 there is a diagonal nozzle pipe 5| having the transversely directed discharge nozzles 52 and a blast of air may be discharged from said nozzles 52 over the surface of the gravel to blow off any light particles of wood, or other foreign matter mixed with the gravel. These light particles will be blown over the upstanding side retainer 53, of the platform 38 and will fall down between said side retainer and the adjacent side I of the frame which is spaced out therefrom. The platform and its end sections 40, 4| may be so adjusted as to permit the gravel to move in a single layer thereover so that said light particles may be thoroughly removed therefrom. The retainer 53 is vertically adjustable relative to the platform.

Underneath and secured to the platform 38 there is a boss 54 and there is a pneumatic hammer 55 arranged to operate against said boss tovibrate the platform so that the light objects to be removed will gradually work up to the top within the range of the blast from the nozzles 52. This hammer is adjustably secured to an arcuate bracket 58 which is bolted to'the underside of' the platform 38. Arcuate rows of perforations 5! are provided through the platform 38 for the bolts which secure the bracket 56 in place and said bracket may thus be adjusted about a vertical axis and the hammer may be adjusted about said bracket so that the direction of the hammer strokes against said boss may be varied.

The bearings in which the shaft 36 rotates are vertically adjustable by means of the adjusting screws 58, 58, so that the brush 3'! may be adjusted as the platform 38 is adjusted, or relative to said platform. The brush has radial relatively stiff, needle-like bristles'which pierce the lumps of clay, and the like, mixed with or adhering to If sand is to be screened the drums 2, 3 should,

be concaved, as shown in Figure 2 so that the cables 4 will be held closely together and the rollers 4 should be adjusted up slightly above the level of said drumsso as to slightly arch the screen and this will have the effect of holding the runs of the screen in transverse alignment and will prevent the side slapping of said runs.

A uniform tension onthe cables 4 may be maintained by tensioning devices, such as illustrated in Figure 13 and which will now be described:Each tensioning device is mounted to move on a track as 62 suitably fixed in position, and is provided with rollers 63 which run on said track. The tensioning device has a casing composed of the side plates 64, 64 and between these plates the sheave 9 is mounted to rotate. These side plates have the aligned slots 65 in one of which a bearing block 66 is slidably mounted and the sheave 9 has a spindle 6'! which rotates in a bearing in said block. There is a retainer 68 having a central boss 69 which works through the other slot 65 and the retainer is secured to the sheave 9 by the set bolt 10. The retainer rides against the adjacent side plate 64 and serves to hold the sheave 9 in proper alignment. Clamped to the bearing block 69 there is a leaf spring H, opposing which and adjustably attached to one of the side plates 64 there is another leaf spring 12 whose ends are attached to the corresponding ends of the spring H. The bearing block 66, on which the sheave 9 has a bearing, is thus yieldingly mounted.

Between the plates 64, 64 there is a friction wheel 13 which is fixed on a stub shaft '14 which is rotatable in a bearing carried by one of the plates and fixed on the outer end of the shaft '54 there is a beveled pinion 76 which is in mesh with and. drives a similar beveled pinion H which is fixed on one end of the shaft 18. This shaft is mounted to rotate in bearings 19, 19 carried by said last mentioned plate 94 and has a worm gear 89 fixed on the other end thereof and which is in mesh with a similar gear 8| which is fixed on the outer end of the shaft 82. The shaft 82 is mounted to rotate in suitable, transversely aligned, bearings carried by the side plates 64 and has a spur gear 83 fixed thereon which is in mesh with the rack 84 into which the adjacent margin of the track 82 is formed. The friction wheel 12 is located within the overhanging rim 85 of the sheaves. As the cable 4 acquires slack the springs H, 72 will cause the sheave 9 to move so as to bring the rim 85 into frictional contact with the wheel it! which will be thereby rotated. The shaft 78 will be correspondingly rotated and the gear 8! and shaft 82 turned to effect the movement of the entire tensioning device along the track 62 to take up the slack of the cable until the resistance of the cable on the sheave 9 is sufiicient to release the rim 85 from the friction wheel 13.

In the modified form shown in Figures 6 and 7 a plurality of series of cables 4 are provided and arranged, as shown, to form screens one above the other. .These series of cables operate over the spaced drums 2, 3 respectively, and pass over the respective outer and inner idler rollers 5, 6 and around the respective idler drums I, 8', and through the tensioning devices I0, I I, all as hereinbefore stated. The screening cables of the screens, in this form are spaced so that the aggregate will be graded, each screen retaining coarse aggregate than the one beneath and the washing fluid and detritus will be collected in the hopper 21,beneath the lower screen and discharged therefromthrough the deliverychute28. The gravel, or other aggregate may be delivered onto the upper screen through the chute l2 and the coarser gravel, retained on said upper screen, will be delivered from said upper screen through the chute 86. The aggregate retained on the other screens may be delivered therefrom through the chutes 87, 88, which have associated flushing nozzles 89, 99.

The chute 87 is arranged to deliver the gravel therefrom onto the grate 2!, as shown in Figure 7, and the gravel, or other aggregate thus delivered then passes on over the platform 38 and is ultimately delivered out through the conveyor 24 and during such passage is washed and cleansed in the manner and by the instrumentalities hereinabove described in connection with the description of Figure 4. The aggregate delivered through the chute 88 passes onto the grate 2| and thence along through a conditioning apparatus similar to and underneath that shown in Figure 7.

In Figure 8 there is shown a slightly modified type of screen wherein a single, endless cable 9| is employed. This cable runs in spiralled fashion over the drums 2, 3 and is formed into a free loop 92 which runs over the idler sheaves 93, 93, and about the sheaves as 9 in the tensioning device as l9, ll of the form shown in Figure l2. A

modified form of tensioning device is shown in Figures 9 and 10 wherein the shaft of the drum 2 is extended and has the friction disc 94 fixed thereon. Underneath the drum 2 there are the series of small grooved pulleys 95, 96 which are fixed on the respective transverse shafts 97, 93 over which alternate cables 4 run. The ends of the shafts 97, 98 are extended and fixed thereon are the grooved friction discs 99, I 90. As the disc 94 rotates it will turn the discs 99, Hit and the corresponding shafts 97, 98 and the shafts 95, 98 fixed thereon. The discs 95, 99 are so proportioned in size relative to that of the discs 94, 99 that the cables 4 will not be fed by said sheaves 95 and 96 at the normal rate of movement of said cables, thus necessitating a certain amount of slippage of the cables over the sheaves 95, 99 thus providing a braking eifect and increasing the tension on the horizontal runs of the cables keeping said horizontal runs taut.

The drawings and description disclose what is now considered to be preferred forms of the invention by way of illustration only, while the broad principle of the invention Will be defined by the appended claim.

What I claim is:

A machine for screening and conditioning gravel and the like including a screen, means for supporting the screen, means for advancing the screen, a platform arranged to receive and conductthe material delivered from the screen, a conveyor having a rotatable brush therein arranged to receive the material from said platform, means for delivering a washing fluid onto the moving material and a chute for collecting said washing fluid and for delivering the same into said conveyor.

JAMES A. WEBB. 

